1. Field of the Invention
The present invention relates to a method and an apparatus for confirming matching of data in a distributed processing system, which are suitable for use of a CAD (computer aided design) system made up of a server and plural clients.
2. Description of Related Art
A CAD system employing a distributed system as shown in FIG. 20 has widely spread in these years at a job site where products are designed or manufactured. Such CAD system is configured with a server 1 and plural clients (terminal equipments such as workstations) 2 and 3 connected to each other through a local area network (referred simply as a LAN, hereinafter) laid in a compound or an office.
Referring to FIG. 20, reference numeral 4 denotes a gateway machine (a GW machine), 51 denotes a basic LAN, 52 denotes a sectional LAN, 53 a transceiver, and 54 denotes a terminal resistor.
The server 1 stores or manages a product database such as drawings of parts of products, three-dimensional data, etc., which is connected to the basic LAN 51 through the transceiver 53. The basic LAN 51 is a basic network, which is connected to the sectional LAN 52 provided for each section (for example, a designing section, a manufacturing section, etc.) through the gateway machine 4.
The sectional LAN 52 is connected to plural clients (only clients 2 and 3 are shown in FIG. 20) through the transceiver 53. The clients 2,3 can make a request for information in the database from the server 1 to refer to or update the database.
In an operation of the CAD system in a distributed processing system configured around the server 1 of this sort, to maintain matching of the data of a product made through the CAD system is sometimes a big problem.
If plural design groups design, in cooperation, one product, or if a manufacturing section and a designing section examine or alter a design of a product in parallel, the work of the design is carried out in the clients 2,3 dispersed in each group or section. As a result, each designer manages the design data in a different way so that it is difficult to manage the CAD data uniformly.
For instance, if a designer calls out the data base from the server 1 through the client 2 for a design work and stores the CAD data after the design work as sub-database in the client 2, the database in the server 1 is not updated and the old data before the design work remains in the server 1. Under such situation, if another designer takes out the database from the server 1 to do a design work through the client 3, the designer cannot confirm matching of the CAD data.